Cochannel interference in ATSC passive radar

This paper presents results of a simulation study quantifying the expected importance of cochannel interference (CCI) in a passive radar using Advanced Television Systems Committee (ATSC) illuminators. CCI stations broadcasting on the same frequency as the illuminator are modeled as additional direct path interference. It is found that spatial nulls alone can be insufficient to suppress CCI in small airborne radars, which might observe up to 10 significant CCIs for each illuminator. A proposed hybrid algorithm uses remodulation to suppress the strongest CCI and nulls only CCI that cannot be decoded. This method improves predicted coverage as compared to nulls alone.